What culture, indeed. I think I am trying to identify and understand the problem in order to be able to consider solutions. We might say that the problem is consumer culture - or it might be tribalism - or it might be any combination of a thousand things. But that approach is identifying the symptoms of the problem and not its root.
As I wondered above, is the root some defect of human nature? Is it learned? A combination of both? We need to understand what it is.
My instinctual approach is to try and manifest forms of possible solutions rather than intellectually formulate them. I don't have much faith in conceptual solutions that prescribe cultural change.
Is revolution a viable option for achieving cultural change? I think it is and has often been manifested, but it is generally a very rough tool and seldom seems to have a well-reasoned and sustainable future outcome. The American Revolution appears to have been a better example of cultural change by fighting - the Civil War was a far worse example (many of the core issues remain unresolved). It is notable that the AR had a carefully stated Declaration, which named issues and desired conditions - the GND movement appears to be following that example.
Another example given in the article is when a deeply shared cause results in people working more cooperatively (warring against other tribes) with "shared sacrifice" becoming a top cultural value. That term lit me up, wondering why "shared benefits" couldn't be as effective a motivator as shared sacrifice.
You mentioned a few intentional examples of people working cooperatively, the Mondragon Coop as one, where the objective was shared benefits instead of shared sacrifice. Two of my life inspirations are the Civilian Conservation Corps and WPA, and Roycroft. I think we are getting warmer...
The GND has potential if it figures out how to manifest its values in solid and pragmatic works, around which policy and culture can develop. If it languishes primarily in the intellectual and disputed world of broad concepts and policy, it will not go far or solve any problems. Change will be more substantial if people desire it in a positive way.
The enlightened leaders (did I say 'elite'?) need to be living the reformed culture, not just talking about it. And anyone who does this will be a leader.
You never change things by fighting the existing reality. To change something, build a new model that makes the old model obsolete. R. Buckminster Fuller